What would cause lead rings in the chamber throats

[foxtrapper]

480 Bisley sixshots powder coated plain base Miha’s 13.5 hs-6 standard cci primer. Hmmmmmm

[Alaskan454]

There are a few threads about this in Ruger 480s. I have these show up with coated and plain lead bullets. Either way, the revolver is superbly accurate so I'm not in a hurry to modify anything.

[foxtrapper]

Jan 28, 2018 20:28:30 GMT -5 Alaskan454 said:

There are a few threads about this in Ruger 480s. I have these show up with coated and plain lead bullets. Either way, the revolver is superbly accurate so I'm not in a hurry to modify anything.

Thanks I’ll go poking around. I heard the barrels could be rough didn’t realize there were cylinder issues too!

[jjsharpshooter]

Here's a post from 2 years ago about my 480 Bisley doing that when I tried powder coating that bullet. I've since changed to lubing traditionally and no more rings.
singleactions.proboards.com/thread/16063/ring-lead-cylinder

[Odin]

Had the same problem with the MP-477-640 in two different revolvers. It wasn't the guns, it was the bullet. Upon ignition the ridge between the two crimp grooves was tearing off as it passed the crimp in the case. Now I no longer crimp with low and midrange loads as case tension holds the bullet just fine. And with stouter loads I run a harder alloy with a good crimp and the issue hasn't raised its head again.

The other option was to simply use the rear crimp groove, but I didn't want to change loads or have my POI change with deeper seating, so I never took that path.

-Rod

[sixshot]

I always use the bottom crimp groove with that bullet.

Dick

[foxtrapper]

Thanks to all! Gonna start with the lower crimp groove as a fix.

[ebg3]

I had a bad issue with leading, lead in the chambers, and lead on case mouths when I tried the Lee 400gr bullet that I cast and powder coated. I felt like the bullets were too soft even with the powder coating. Maybe the baking was softening the bullets. My alloy is isotope lead with some tin added. I tried HS-6, 2400, and H110 with this bullet and had the leading blowback issue with all combos. The lower pressured loads seemed to be less but it was still too much.
I switched to a RCBS 400gr swc mold and lube/sized to .476 with a soft lube and the lead blow back went away completely. This bullet is very accurate and has huge grease grooves. I still get some leading in the bad/pitted area in my barrel, after 40-50 rounds, but it is not too bad. My current load is 18.5gr 2400 with the 400gr RCBS bullet.

[zeus]

Jan 29, 2018 0:06:45 GMT -5 Odin said:

Had the same problem with the MP-477-640 in two different revolvers. It wasn't the guns, it was the bullet. Upon ignition the ridge between the two crimp grooves was tearing off as it passed the crimp in the case. Now I no longer crimp with low and midrange loads as case tension holds the bullet just fine. And with stouter loads I run a harder alloy with a good crimp and the issue hasn't raised its head again.

The other option was to simply use the rear crimp groove, but I didn't want to change loads or have my POI change with deeper seating, so I never took that path.

-Rod

I should have never let that bullet come out with two crimp grooves when we did it the first time. I was asked to and it has bothered me ever since. 😩

[bushog]

Jan 29, 2018 0:06:45 GMT -5 Odin said:

Had the same problem with the MP-477-640 in two different revolvers. It wasn't the guns, it was the bullet. Upon ignition the ridge between the two crimp grooves was tearing off as it passed the crimp in the case. Now I no longer crimp with low and midrange loads as case tension holds the bullet just fine. And with stouter loads I run a harder alloy with a good crimp and the issue hasn't raised its head again.

The other option was to simply use the rear crimp groove, but I didn't want to change loads or have my POI change with deeper seating, so I never took that path.

-Rod

Good info but question......

"The other option was to simply use the rear crimp groove, but I didn't want to change loads or have my POI change with deeper seating, so I never took that path."

Rear crimp grove leads to deeper seating?

I'm guessing that's not what you meant....

[bula]

Think on a bullet that big two cannelures can be done well enough. Do wish they were a bit more substantial and a little further apart allowing that ring between to be sturdier. Let's not forget he bullet has been very successful in the field though ! After reading the early reports on the lead rings, which I got to read before getting my hands on the bullets I just chose to always use the lower crimp point. Hoover-san said something about ignoring the ring, he hadn't had the gun tie up or fail yet. So..

[Odin]

Jan 29, 2018 9:06:15 GMT -5 bushog said:

Jan 29, 2018 0:06:45 GMT -5 Odin said:

...I'm guessing that's not what you meant....

You're right.

To clarify, I simply didn't want anything to change POI/velocity-wise as it was pretty close to the opener of deer season. Using the rear crimp groove would seat the bullet out FURTHER not DEEPER. Duh!!!

Crimping just to straighten the case worked just fine and my POI didn't change a lick, so I just kept up with the practice.

[Odin]

Jan 29, 2018 8:59:39 GMT -5 zeus said:

I should have never let that bullet come out with two crimp grooves when we did it the first time. I was asked to and it has bothered me ever since. 😩

A lil alloy adjustment and/or change of crimp technique and the problem simply vanishes. Considering some of the nagging issues that can surface with sixguns, I consider such troubles pretty low on my list of things to worry about.

[2 Dogs]

Jan 29, 2018 8:59:39 GMT -5 zeus said:

Jan 29, 2018 0:06:45 GMT -5 Odin said:

Had the same problem with the MP-477-640 in two different revolvers. It wasn't the guns, it was the bullet. Upon ignition the ridge between the two crimp grooves was tearing off as it passed the crimp in the case. Now I no longer crimp with low and midrange loads as case tension holds the bullet just fine. And with stouter loads I run a harder alloy with a good crimp and the issue hasn't raised its head again.

The other option was to simply use the rear crimp groove, but I didn't want to change loads or have my POI change with deeper seating, so I never took that path.

-Rod

I should have never let that bullet come out with two crimp grooves when we did it the first time. I was asked to and it has bothered me ever since. 😩

We have the option of redesigning that bullet specifically for the new Ruger. I’ll check with BobK.

[2 Dogs]

Jan 29, 2018 7:17:09 GMT -5 ebg3 said:

I had a bad issue with leading, lead in the chambers, and lead on case mouths when I tried the Lee 400gr bullet that I cast and powder coated. I felt like the bullets were too soft even with the powder coating. Maybe the baking was softening the bullets. My alloy is isotope lead with some tin added. I tried HS-6, 2400, and H110 with this bullet and had the leading blowback issue with all combos. The lower pressured loads seemed to be less but it was still too much.
I switched to a RCBS 400gr swc mold and lube/sized to .476 with a soft lube and the lead blow back went away completely. This bullet is very accurate and has huge grease grooves. I still get some leading in the bad/pitted area in my barrel, after 40-50 rounds, but it is not too bad. My current load is 18.5gr 2400 with the 400gr RCBS bullet.

My 480 Ruger is going to require a .477” plus bullet. It’s quite possible you’re in the same boat and getting some gas blow by. Let me know if you would like me to measure your cylinder throats and your cast bullets to see if a change in bullet size might help.